Filter element for pulse cleaning and methods

ABSTRACT

A filter element includes a media pack of Z-media having first and second opposite flow faces and a side wall extending between the first and second flow face. A gasket is secured to the side wall. The gasket has a sealing portion and an attachment portion. The sealing portion has a flat surface at least one inch long and is located between being planar with and 0.5 inches recessed from the first flow face, inclusive. The filter element can be used in a dust collector.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. Ser. No.15/679,704, filed Aug. 17, 2017, which is a continuation application ofU.S. Ser. No. 15/349,096, filed Nov. 11, 2016, which is a continuationapplication of U.S. Ser. No. 14/036,740, filed Sep. 25, 2013, whichissued on Nov. 29, 2016 as U.S. Pat. No. 9,504,948, which is adivisional application of U.S. Ser. No. 12/919,398, filed Nov. 4, 2010,which issued on Oct. 1, 2013 as U.S. Pat. No. 8,545,585, which is a USNational Stage of PCT International Patent application No.PCT/US2009/034853, filed Feb. 23, 2009 in the name of Donaldson Company,Inc., a U.S. national corporation, applicant for the designation of allcountries except the US, and Thomas D. Raether, a citizen of the U.S.,applicant for the designation of the US only, and claims priority toU.S. Provisional patent application Ser. No. 61/067,173, filed Feb. 25,2008 and which applications are incorporated herein by reference. To theextent appropriate, a claim of priority is made to each of the abovedisclosed applications.

TECHNICAL FIELD

This disclosure relates to methods for pulse cleaning filter elementsutilizing pressurized gas generators. This disclosure also relates toapparatus including air cleaners, dust filters, and pulse cleaningtechnology.

BACKGROUND

Air cleaners or dust collector devices sometimes use exhaust gas from avalve and pressure tank (reservoir) to back flush filters. Examples ofsuch air filters assemblies are disclosed in, for example, U.S. Pat.Nos. 6,090,173; 4,218,227; 4,395,269; 5,980,598; 6,322,618; DE 3905113;and Patent Publication U.S. 2006/0112667A1, each of these patentdocuments being incorporated by reference herein.

Effective cleaning of these filters requires that the exhaust jet fillthe opening of the filter to be cleaned. In many implementations, theopening of the filter corresponds to the opening in the tubesheet, inwhich the filter is mounted. Improvements in pulse cleaning filters aredesirable.

SUMMARY

To improve in pulse cleaning of filters, a filter element is providedincluding a media pack of Z-media having first and second opposite flowfaces and a side wall extending between the first and second flow face.A gasket is secured to the side wall. The gasket has a sealing portionand an attachment portion. The sealing portion has a flat surface atleast one inch long and is located between being planar with and 0.5inches recessed from the first flow face, inclusive.

In another aspect, a dust collector is provided including a housing witha dirty air inlet, a clean air outlet, and an interior; a tubesheet inthe housing interior having a plurality of openings; a plurality ofpanel-style filter elements mounted in a respective one of the openingsin the tubesheet; and a plurality of blowpipes, with each being orientedto direct a fluid pulse at a respective one of the panel-style filterelements. The filter elements include a media pack of Z-media, a gasketthat is between planar with and 0.5 inches recessed from the first flowface, in which the gasket forms a seal with the tubesheet. The blowpipesdirect a pulse at an angle that is not normal to a plane of the openingsin the tubesheet and not in line with a general direction of filtrationflow through the filter element.

In another aspect, a method of cleaning a filter element installed in adust collector includes providing a filter element, as mentioned above,and periodically pulsing a jet of gas into the downstream flow face tocause at least some particulate material on an upstream side of theZ-media to be removed from the Z-media.

Not all the features described herein must be incorporated in anarrangement for the arrangement to have some selected advantage,according to the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view, partially broken away, of oneembodiment of an air filter system utilizing principles of thisdisclosure;

FIG. 2 is a schematic side elevational view illustrating principles ofthis disclosure;

FIG. 3 is a schematic diagram illustrating principles of thisdisclosure;

FIG. 4 is a perspective view of a filter element usable with the airfilter system of FIG. 1, designed in accordance with principles of thisdisclosure;

FIG. 5 is an enlarged, partial cross-sectional view of a portion of thefilter element of FIG. 4; and

FIG. 6 is an alternate embodiment of the filter element depicted in FIG.5.

DETAILED DESCRIPTION

A dust filter or air cleaner system is depicted generally at 10 inFIG. 1. The system depicted includes a housing 12 having a side wallpanel 17 broken away to illustrate the arrangement of various portionsof the assembly. An upper wall panel 16 has an inner wall surface 19. Inthis embodiment, an air inlet 20 is positioned in the upper wall panel16 so that the particulate-laden air or other fluid is introduced intoan unfiltered (dirty) fluid chamber 22. The unfiltered chamber 22 isdefined by an access door 13, the upper wall panel 16, opposing sidewall panels 17, a tubesheet 28, and a bottom surface 23 partiallydefining a collection area or hopper 25. The bottom base panel or frame26 is secured to the side wall panels 17 in a suitable manner.

As mentioned above, the tubesheet 28 is mounted in the interior of thehousing 12. The tubesheet 28 includes a plurality of openings 30. Withineach opening 30 is mounted an individual filter element, which in theillustrated embodiment, is a panel-style filter element 32. By the term“panel-style filter element” it is meant an element with filter media inwhich, in general, fluid to the filtered flows through the filterelement in a straight-flow thorough manner. For example, a panel-stylefilter element can be pleated media, depth media, fluted media, Z-mediaincluding a z-filter construction, or mini V-packs. By “Z-media”, it ismeant media having first and second opposite flow faces with a pluralityof flutes, each of the flutes having an upstream portion adjacent to thefirst flow face (so that the first flow face is an inlet flow face,where air to be filtered flows in) and a downstream portion adjacent tosecond flow face (so that the second flow face is an outlet flow face,where filter air exits the element), selected ones at the flutes beingopen at the upstream portion and closed at the downstream portion, whileselected ones of the flutes are closed at the upstream portion and openat the downstream portion. The flutes can be straight, tapered, ordarted. The flutes extend between the inlet flow face and the outletflow face. Examples of filter elements with Z-media are found in, forexample, U.S. Pat. No. 5,820,646; Patent Publication 2003/0121845; andU.S. Pat. No. 6,350,291, each of these patent documents beingincorporated by reference herein.

The term “z-filter construction” as used herein, is meant to refer to afilter construction in which individual ones of corrugated, folded orotherwise formed filter flutes are used to define sets of longitudinalfilter flutes for fluid flow through the media; the fluid flowing alongthe length of the flutes between opposite inlet and outlet flow ends (orflow faces) of the media. Some examples of z-filter media are providedin U.S. Pat. Nos. 5,772,883; 5,902,364; 5,792,247; 5,895,574; 6,210,469;6,190,432; 6,350,296; 6,179,890; 6,235,195; Des. 399,944; Des. 428,128;Des. 396,098; Des. 398,046; and, Des. 437,401; each of these fifteencited references being incorporated herein by reference.

One type of z-filter media utilizes two specific media components joinedtogether, to form the media construction. The two components are: (1) afluted (typically corrugated) media sheet; and, (2) a facing mediasheet. The facing media sheet is typically non-corrugated, however itcan be corrugated, for example perpendicularly to the flute direction asdescribed in U.S. provisional 60/543,804, filed Feb. 11, 2004,incorporated herein by reference.

The fluted (typically corrugated) media sheet and the facing mediasheet, together, are used to define media having parallel inlet andoutlet flutes; i.e. opposite sides of the fluted sheet operable as inletand outlet flow regions. In some instances, the fluted sheet andnon-fluted sheet are secured together and are then coiled to form az-filter media construction. Such arrangements are described, forexample, in U.S. Pat. Nos. 6,235,195 and 6,179,890, each of which isincorporated herein by reference. In certain other arrangements, somenon-coiled sections of fluted media secured to flat media, are stackedon one another, to create a filter construction. An example of this isdescribed in FIG. 11 of U.S. Pat. No. 5,820,646, incorporated herein byreference.

Typically, coiling of the fluted sheet/facing sheet combination arounditself, to create a coiled media pack, is conducted with the facingsheet directed outwardly. Some techniques for coiling are described inU.S. provisional application 60/467,521, filed May 2, 2003 and PCTApplication US 04/07927, filed Mar. 17, 2004, published Sep. 30, 2004 asWO 2004/082795, incorporated herein by reference. The resulting coiledarrangement generally has, as the outer surface of the media pack, aportion of the facing sheet, as a result. In some instances a protectivecovering can be provided around the media pack.

The term “corrugated” when used herein to refer to structure in media,is meant to refer to a flute structure resulting from passing the mediabetween two corrugation rollers, i.e., into a nip or bite between tworollers, each of which has surface features appropriate to cause acorrugation affect in the resulting media. The term “corrugation” is notmeant to refer to flutes that are formed by techniques not involvingpassage of media into a bite between corrugation rollers. However, theterm “corrugated” is meant to apply even if the media is furthermodified or deformed after corrugation, for example by the foldingtechniques described in PCT WO 04/007054, published Jan. 22, 2004,incorporated herein by reference.

Corrugated media is a specific form of fluted media. Fluted media ismedia which has individual flutes (for example formed by corrugating orfolding) extending thereacross.

Serviceable filter element or filter cartridge configurations utilizingz-filter media are sometimes referred to as “straight through flowconfigurations” or by variants thereof. In general, in this context whatis meant is that the serviceable filter elements generally have an inletflow end (or face) and an opposite exit flow end (or face), with flowentering and exiting the filter cartridge in generally the same straightthrough direction. (The term “straight through flow configuration”disregards, for this definition, any air flow that passes out of themedia pack through the outermost wrap of facing media.) The term“serviceable” in this context is meant to refer to a media containingfilter cartridge that is periodically removed and replaced from acorresponding air cleaner. In some instances, each of the inlet flow endand outlet flow end will be generally flat or planar, with the twoparallel to one another. However, variations from this, for examplenon-planar faces are possible.

In general, the media pack includes appropriate seal material therein,to ensure there is no unfiltered flow of air through the media pack, inextension from front flow face (an inlet flow face) completely throughand outwardly from opposite oval face (outlet flow face).

A straight through flow configuration (especially for a coiled mediapack) is, for example, in contrast to serviceable filter cartridges suchas cylindrical pleated filter cartridges of the type shown in U.S. Pat.No. 6,039,778, incorporated herein by reference, in which the flowgenerally makes a turn as its passes through the serviceable cartridge.That is, in a U.S. Pat. No. 6,039,778 filter, the flow enters thecylindrical filter cartridge through a cylindrical side, and then turnsto exit through an end face (in forward-flow systems). In a typicalreverse-flow system, the flow enters the serviceable cylindricalcartridge through an end face and then turns to exit through a side ofthe cylindrical filter cartridge. An example of such a reverse-flowsystem is shown in U.S. Pat. No. 5,613,992, incorporated by referenceherein.

The term “z-filter media construction” and variants thereof as usedherein, without more, is meant to refer to any or all of: a web ofcorrugated or otherwise fluted media secured to (facing) media withappropriate sealing to inhibit air flow from one flow face to anotherwithout filtering passage through the filter media; and/or, such a mediacoiled or otherwise constructed or formed into a three dimensionalnetwork of flutes; and/or, a filter construction including such media.In many arrangements, the z-filter media construction is configured forthe formation of a network of inlet and outlet flutes, inlet flutesbeing open at a region adjacent an inlet face and being closed at aregion adjacent an outlet face; and, outlet flutes being closed adjacentan inlet face and being open adjacent an outlet face. However,alternative z-filter media arrangements are possible, see for example US2006/0091084 A1, published May 4, 2006, incorporated herein byreference; also comprising flutes extending between opposite flow faces,with a seal arrangement to prevent flow of unfiltered air through themedia pack.

In operation, fluid, such as air, to be filtered flows into the system10 through the inlet 20. From there, it flows through the filterelements 32. The filter elements 32 remove particulate material from thefluid. The filtered fluid then flows into the clean air or filtered flowchamber 15. From there, the clean air flows through an outlet 34.Periodically, the filter elements 32 will be cleaned by pulsing a fluidjet, such as a jet of air, from a downstream side 36 of the filterelement 32 to an upstream side 38 of the filter element 32.Specifically, a jet of pressurized gas will be directed throughindividual blow pipes 40, a respective blow pipe being oriented for eachof the respective filter elements 32. This will direct the jet througheach filter element 32, from the downstream (outlet) side 36 to theupstream (inlet) side 38. This helps to knock debris and particulatefrom the upstream side 38 of the filter element 32, directing it off thefilter element 32 and into a hopper.

A schematic illustration of the portion of the system 10 is illustratedin FIG. 2. In FIG. 2, the blow pipe 40 can be seen oriented with respectone the filter elements 32 in the opening 30 in the tubesheet 28. InFIG. 2, it can be seen how the blow pipe 40 is oriented relative to thefilter element 32 in a plane 60 (FIG. 3) that contains the respectiveopening 30 in the tubesheet 28 for the respective filter element 32,such that a pulse that comes from the blow pipe 40 is at an angle thatis not normal to a plane of the opening 30 and is not in line with ageneral direction of filtration flow thorough the filter element 32. Bythe term “not normal”, it is meant non-orthogonal, such as at an acuteor obtuse angle relative to the plane 60 that contains the opening 30for the respective filter element 32. By “not in line with a generaldirection of filtration flow”, it is meant, for a straight-through flowfilter, the pulse flow is in a direction that is not parallel to theflow of direction through the filter element 32. By directing the fluidpulse at the filter element 32 at such an angle 64, the exhaust jet,which expands at a predictable angle, creates a diameter D2 (FIG. 3)larger in one direction that a diameter D1 that is typically used in theprior art.

While the illustrated embodiment shows only a single blowpipe 40corresponding to a single filter element 32, it should be understoodthat in many implementations, there are more than one blowpipe 40 foreach element 32.

In some embodiments, at least a portion of the pulse can be trapped byusing an optional accumulator arrangement 42. The accumulatorarrangement 42 captures the flow of the pulse from the blow pipe 40. Inone embodiment, the accumulator arrangement 42 includes a least oneplate, shown as first plate 44, oriented on the clean air side 15 of thetubesheet 28 and adjacent to the opening 30 of the tubesheet 28. Thefirst plate 44 may be any type of wall, sheet metal, panel, baffle,rigid plastic, or generally non-porous solid structure that is orientedto the adjacent respective opening in the tubesheet 28 for therespective filter element 32.

In certain implementations, the accumulator arrangement includes asecond plate 46 oriented at an opposite end of the opening 30 at thetubesheet 28 from the first plate 44. In the embodiment shown, the firstand second plates 44, 46 are aligned with the general direction of thepulse, but the angle does not necessarily need to be the same as theangle of the pulse direction. FIG. 2 illustrates a center line of thedirection of the pulse at 48. The first plate is mounted at a firstangle 50 relative to the tubesheet 28. The first angle is within about5° of center line 48 of a direction of the pulse. Similarly, the secondplate 46 is mounted at a second angle 52 relative to the tubesheet 28.The second angle 52 is within about 5° of the center line 48 of adirection of the pulse. In some embodiments, the first angle 50 and thesecond angle 52 are equal. In other embodiments, the first angle 50, andsecond angle 52 are unequal. In some embodiments, the first angle 50 andthe second angle 52 are within 30° of being parallel to each other. Theangles 50, 52 of the plates 44, 46 are selected based upon the angle 64of the pulse.

As illustrated in FIG. 2, the first plate 44 has length L₁, which ispreferably no longer than three times the length of the respectiveopening 30 in the tubesheet 28. This is because primary flow pressureloss increases with increase in length. Preferably, the length L₁ has alength that is between 25-75% of a length of the respective opening 30in the tubesheet 28. In preferred embodiments, the blowpipe 40 is spacedno more than 30-40 times of an inside diameter of the blowpipe from thetubesheet to eject the pulse.

In FIG. 2, reference numeral 72 shows the offset between the pulsecenter line 48 and a center of the filter element 32. This shows how thecenter line 48 of the pulse is not always in alignment with the centerof the filter element 32.

In one embodiment, the plate that is closer to the respective blow pipe40 (in the embodiment illustrated, the second plate 46) has a lengththat is shorter than the other plate (in this example, the first plate44). In one embodiment, this shorter plate 46 has a length that is notless than 5% of a length of the respective opening 30 in the tubesheet28. This arrangement is advantageous because of both material savingsand pressure loss associated with pumping air flow.

Attention is directed to FIG. 3. In FIG. 3, the arrow 62 represents theprior art pulse direction. In the prior art, the standard pulsedirection is directed perpendicular or normal to the plane 60 thatcontains the tubesheet 28. Angle 64 shows the angle that is offset tothe vertical direction, or the direction from the standard, prior artdirection shown by arrow 62. A typical pulse expansion is shown at angle66, from the blow pipe 40. As explained above, the exhaust jet from theblow pipe 40 creates a diameter D2, covering a larger surface area inthe opening 30 of tubesheet 28, versus diameter D1 that comes from theexhaust jet shown at arrow 62 in the prior art arrangement.

One useful arrangement has the following angles and dimensions: Angle 64is 25°-35°, preferably 29°; angles 50 and 52 are equal and 18°-25°,preferably 22°-23°; first and second plates 44, 46 are parallel; offset72 is about 1 inch; length L1 is about 16-20 inches, preferably about18.75 inches; and length L2 is about 6-10 inches, preferably about 8.0inches.

FIGS. 4-6 depict useful embodiments for the filter element 32 in thecollector housing 12. Filter element 32 includes a media pack 80 ofZ-media. The media pack 80 has first and second opposite flow faces 81,82 and a side wall 83 extending between the first and second flow faces81, 82. In implementation, the first flow face 81 also corresponds tothe downstream (outlet) flow face 36, while the second flow face 82corresponds to the upstream (inlet) flow face 38.

In the embodiment shown, the media pack 80 includes a non-cylindricalpack of media that is a coiled construction 86. In alternativeembodiments, the media pack 80 can be a construction of stacked Z-media.The coiled construction 86 has an overall cross-sectional shape that canbe oval or race track-shaped. In the embodiment shown, the media pack 80is race track-shaped in that it has a pair of straight parallel sides88, 89 joined by rounded ends 90, 91. In other embodiments, the mediapack 80 can be round or rectangular, or rectangular with roundedcorners.

In general, the filter element 32 includes a handle member 94 extendingaxially from the first flow face 81. In this embodiment, the handlemember 94 includes a projection 96 defining an open aperture 98 sized toaccommodate a human hand. The filter element 32 can be made generally inaccord with U.S. Pat. No. 6,235,195, incorporated herein by reference.

In this embodiment, the filter element 32 includes a central core 100embodied as a flat board. The media pack 80 is coiled around the core100. The core 100 projects above the first flow face and defines thehandle member 94 for manipulating the filter element 32.

The filter element 32 further includes a gasket 102. The gasket 102 issecured to the side wall 83. In preferred implementations, the gasket102 is molded directly to the side wall 83 of the media pack 80. Inother embodiments, the gasket 102 can be pre-made through, for example,an extrusion process and then attached to the side wall 83 of the mediapack 80 by glue or an adhesive.

In accordance with principles of this disclosure, the gasket 102 issecured to the side wall 83 so that it is between planar with and 0.5inches recessed from the first flow face 81, inclusive. In other words,the gasket 102 is either completely even with (planar with) the firstflow face 81 or it is located no greater than 0.5 inches recessed awayfrom the first flow face 81, inclusive. By the term “inclusive” it ismeant that the gasket 102 can be even with the flow face 81 or it can be0.5 inches recessed from the first flow face 81, or it can be anywherewithin the range of even with and 0.5 inches recessed from the firstflow face 81. By locating the gasket 102 at this location, it positionsthe media pack 80 in the tubesheet 28 in a way that allows thedownstream flow face 36 to be generally even with the tubesheet 28. Thisresults in more effective pulse cleaning of the filter element 32because less energy is lost when the downstream flow face 36 is evenwith the tubesheet 28.

In the embodiment shown, the gasket 102 has a sealing portion 104 and anattachment portion 106. The attachment portion 106 is the part of thegasket 102 that is directly secured to the side wall 83 of the mediapack 80. The sealing portion 104 is the part of the gasket 102 that iscompressed against the tubesheet 28 to form a seal with the tubesheet28.

In the embodiment shown, the sealing portion 104 has a flat surface 108.The flat surface 108, in practice, is at least one inch long. In FIG. 5,it can be seen how the flat surface 108 is planar with the first flowface 81. In the embodiment of FIG. 6, the flat surface 108 is recessed adistance 110 from the first flow face 81. This distance is not greaterthan 0.5 inches, inclusive.

In reference again to FIG. 5, the gasket 102 defines an undercut 112between the attachment portion 106 and the sealing portion 104. As canalso be seen in FIG. 5, the sealing portion 104 includes a first angledsurface 114 and a second angled surface 116. The first and second angledsurfaces 114, 116 slant toward each other to meet an apex 118. The firstangled surface 114 and the attachment portion 106 are joined at a base120. The first angled surface 114 extends from the attachment portion106 at the base 120 to the apex 118, while the second angled surface 116extends from the flat surface 108 to the apex 118. The undercut 112 isdefined as a gap between the first angled surface 114 and the attachmentportion 106. In the embodiment shown, the attachment portion 106includes an extension that extends from the surface 108 down past theapex 118.

In the embodiment shown, the undercut 112 is defined by a verticaldistance 122 from the base 120 to the apex 118, or end of the firstangles surface 114 shown. This dimension 122 is at least 0.5 inch.

The flat surface 108 slopes downward and away from the first flow face81 at an angle that is greater than zero degrees and less than 20degrees.

In use, the element 32 is installed in dust collector 10 in a mannersuch that the downstream flow face 36 is even with the tubesheet 28 oris less than 0.5 inches recessed from the tubesheet 28, inclusive. Thefilter element 32 can be cleaned by periodically pulsing a jet of fluidor gas into the downstream flow face 36 to cause at least someparticulate material on the upstream side 38 of the Z-media pack 80 tobe removed from the media pack 80.

General Principles

A filter element can include a media pack comprising opposite first andsecond flow faces with flutes extending in a direction therebetween; asidewall extending between the first and second flow faces; one of thefirst and second flow faces being an inlet flow face and the other beingan outlet flow face; and a gasket secured to the sidewall; the gaskethaving a sealing portion and an attachment portion; the sealing portionhaving a flat surface at least one inch long and being between planarwith and 0.5 inches recessed from the first flow face, inclusive.

The media pack may be non-cylindrical.

The media pack may be oval shaped.

The media pack may be racetrack shaped having a pair of straightparallel sides joined by rounded ends.

The gasket can define an undercut between the attachment portion and thesealing portion; the sealing portion can include first and second angledsurfaces slanting toward each other to meet at an apex; the first angledsurface can extend from the attachment portion to the apex; the secondangled surface can extend from the flat surface to the apex; theundercut may be defined as a gap between the first angled surface andthe attachment portion; and the first angled surface and the attachmentportion may be joined by a base.

A vertical distance from the base to an end of the first angled surfacecan be at least 0.5 inch.

The flat surface may slope downward and away from the first flow face atan angle of greater than 0 degrees and less than 20 degrees.

The filter media may be a coiled construction.

A handle member may extend axially from the first flow face.

The handle member may include a projection defining an open aperturesized to accommodate a human hand.

A central core can be included, with the media pack coiled around thecore.

The central core may project above the first flow face and define ahandle member for manipulating the filter element.

A dust collector can include a housing including a dirty air inlet, aclean air outlet, and an interior; a tubesheet in the housing interiorhaving a plurality of openings; a plurality of panel-style filterelements, each filter element being mounted in a respective one of theopenings in the tubesheet; each of the filter elements including: amedia pack comprising opposite first and second flow faces with flutesextending in a direction therebetween; a sidewall extending between thefirst and second flow faces; one of the first and second flow facesbeing an inlet flow face and the other being an outlet flow face; and agasket secured to the sidewall; the gasket having a sealing portion andan attachment portion; the sealing portion having a flat surface atleast one inch long and being between planar with and 0.5 inchesrecessed from the first flow face, inclusive; the gasket forming a sealwith the tubesheet; a plurality of blowpipes; each blowpipe beingoriented to direct a fluid pulse at a respective one of the panel-stylefilter elements at an angle that is: not normal to a plane of theopenings in the tubesheet; and not in line with a general direction offiltration flow through the respective panel-style filter.

The media pack can be racetrack shaped having a pair of straightparallel sides joined by rounded ends; and the filter media is a coiledconstruction.

A central core can be included with the media pack being coiled aroundthe core; and the central core can projects above the first flow faceand defines a handle member for manipulating the filter element.

The gasket can define an undercut between the attachment portion and thesealing portion; the sealing portion including first and second angledsurfaces slanting toward each other to meet at an apex; the first angledsurface extending from the attachment portion to the apex; the secondangled surface extending from the flat surface to the apex; the undercutbeing defined as a gap between the first angled surface and theattachment portion; and the first angled surface and the attachmentportion being joined by a base.

A method of cleaning a filter element installed in a dust collector caninclude providing a filter element of z-media sealed against a tubesheetin a dust collector housing; the filter element having an inlet flowface and an outlet flow face with flutes in between and being sealedagainst the tubesheet so that the outlet flow face is between planarwith and 0.5 inches recessed from tubesheet, inclusive; and periodicallypulsing a jet of gas into the outlet flowface to cause at least someparticulate material on an upstream side of the z-media to be removedfrom the z-media.

The above are examples utilizing principles of this disclosure. Not allthe features described herein must be incorporated in an arrangement forthe arrangement to have some selected advantage, according to thepresent disclosure.

I claim:
 1. A method of installing a filter element into a dustcollector; the method comprising: (a) providing a dust collector havinga dirty air inlet, a clean air outlet, an interior volume, and atubesheet in the interior volume having a plurality of openings; and (b)positioning a filter element in the dust collector by orienting adownstream flow face of the filter element in one of the openings to beeven with or less than 0.5 inches recessed from the tubesheet.
 2. Themethod of claim 1 wherein the step of positioning a filter elementincludes forming a seal between the filter element and the tubesheet bypressing a sealing portion of a gasket secured to the element againstthe tubesheet, the sealing portion having a flat surface.
 3. The methodof claim 2 wherein the step of pressing a sealing portion of a gasketincludes using a gasket having the sealing portion and an attachmentportion secured to a sidewall of the element, the gasket having anundercut between the attachment portion and the sealing portion.
 4. Themethod of claim 2 wherein the step of pressing a sealing portionincludes pressing the flat surface of the sealing portion against thetubesheet, the flat surface sloping downward and away from thedownstream flow face at an angle greater than 0 degrees and less than 20degrees.
 5. The method of claim 2 wherein the step of positioning afilter element includes positioning a filter element having a media packcomprising opposite upstream and downstream flow faces with flutesextending in a direction therebetween.
 6. The method of claim 5 whereinthe step of positioning a filter element includes positioning a filterelement having the media pack in a coiled construction.
 7. The method ofclaim 5 wherein the step of positioning a filter element includespositioning a filter element having the media pack in a non-cylindricalshape.
 8. The method of claim 5 wherein the step of positioning a filterelement includes positioning a filter element having the media pack in aracetrack shaped having a pair of straight parallel sides joined byrounded ends.
 9. The method of claim 1 wherein the step of positioning afilter element includes grasping a handle member extending axially fromthe downstream flow face.
 10. The method of claim 1 wherein the step ofproviding a dust collector includes providing the dust collector with aplurality of blowpipes to direct a fluid pulse at the downstream flowface of the filter element.